Ruthenium Photoactive Dendrimers

Dendrimers are highly defined macromolecules with large tree-like structures, which can be attached to simpler metal complexes, to make use of a physical property of the metal complex.

Scientists from universities in Italy and Germany have now synthesised photoactive dendrimers built around a luminescent [Ru(bpy)3)]2+ core (bpy = 2, 2′-bipyridine), with 12 and 24 luminescent naphthyl units in the periphery (M. Plevoets, F. Vögtle, L. De Cola and V. Balzani, New J. Chem ., 1999, 23, (1), 63-69).

The larger dendrimer core fluoresces three times more than the basic ruthenium complex, showing that very efficient energy transfer is taking place from the naphthyl units to the metal core (antenna effect). This has various applications, such as antenna systems for harvesting energy in sunlight.